Last season's finalists Athletic Bilbao survived a first-half scare to beat Slaven Koprivnica 3-1 at the San Mames in their Europa League third qualifying round first leg.
Ismael Lopez gave the hosts a 16th minute lead at the San Mames before Mateas Delic replied three minutes later for the Croatians.
Markel Susaeta put his side back into the lead a minute later before Lopez was on hand to seal the win after 68 minutes.
Elsewhere, French side Marseille could only draw 1-1 with Turkish outfit Eskisehirspor . The Ligue 1 side took the lead early in the second half through Andre-Pierre Gignac before Atdhe Nuhiu equalized after 62 minutes for the hosts.
Inter Milan eased to a 3-0 first leg win over Hajduk Split thanks to first half strikes from Wesley Sneijder and Yuto Nagatomo, while substitute Coutinho completed the scoring in the 73rd minute.
Heerenveen were the night's biggest winners - defeating visitors Rapid Bucharest 4-0 , while last season's Champions League quarterfinalists, Apoel Nicosia , needed an 80th-minute goal from substitute Efstathios Aloneftis to seal a narrow 2-1 home win over Norway's Aalesund .
Steve McClaren looks set to guide FC Twente through this stage of the competition after seeing off Mlade Boleslav 2-0 .
Leroy Fer and Nacer Chadli were on target for the Dutch outfit against Czech opposition.
Another Eredivisie side to enjoy a productive night were Heerenveen, with Filip Djuricic grabbing a deadly double in a 4-0 stroll past Rapid Bucuresti .
Oleg Shatov and Fyodor Smolov were on target as Anzhi Makhachkala saw off Vitesse Arnhem 2-0, while Marseille were held 1-1 by Eskisehirspor - with Andre-Pierre Gignan on target for the Ligue 1 side.